Beneficiation of acidic minerals



alkyl derivative of guanidine, biguanide, thiourea, guanylurea, or salt thereof.

Patented Dec. 12, 1-944 UNITED. STATES PATENT OFFICE I 2,365,084 7 BENEFICIATION F Acmrc menus David W. Jayne, Jr., Old Greenwich, Harold M. Day, Cos Cob, and Elmer W. Gieseke', Stamford. Conn., assignors to American Cyanamld Company, New York, N. Y., a corporation of Maine No Drawing. Application March 31, 1942, Serial No. 437,037

8 Claims. (0]. 209-166) The present invention relates to mineral concentration and more particularly relates to the use of a new class of reagents for selectively separating acidic minerals from other ore conseparating silica or silicat minerals, such as mica, from non-metallic ores including limestone, bauxite, barytes ilmenite, calcite, and the like, and especially phosphate minerals wherein the silicious gangue is floated away from the phosphate minerals.

In accordance with this'invention natural ores or artificial materials comprising a mixture of acidic minerals with other mineral constituents are subjected to a separation or concentration process in the presence of a promoter for the acidic ore minerals, said promoter being a higher guanyl- The reagentsof the present invention are effective promoters or collectors for negatively charged or acidic ore materials generally and said acidic material may either b worthless gangue or valuabl ore constituents. The most important uses are, however, in connection with the froth floation of silica from non -metallic ores in which the silicious gangue may represent a minor proportion of the ore rather than metallic and sulfide ores in which the gangue usually represents the major proportion of the ore. Representative acidic ore materials are the .feldspars, quartz, Dyroxenes, the spinels, biotite, muscovite, clays. and the like.--"" 1 like.

by the following The compounds that have been found to have a selective filming attraction for acidic ores and which are useful for carrying out this invention include broadly the higher alkyl substituted guanidines, biguanides, guanylthioureas, and guanylureas and salts thereof. Compounds falling within this classification may be represented formula:

in which R is an alkyl radical containing from 8 to 20 carbon atoms, R is hydrogen or an alkyl radical containing from 8 to 20 carbon atoms and Y represents hydrogen, or a radical such as "El-TH, -CNHI, '-C|NH:

and the salts of such compounds. An examination of the general formula shows that the compounds are all lgheralkylated derivatives of guanidines, biguanides, guanylthioureas, guanylureas, and the We have found that while guanidine,

biguanfule, guanylthiourea and'guanylurea, themselves, have no promoter action for acidic ore materials, they can be converted into efiective promoters by replacing at least one of the h'v :lrogens on an aminonitrogen group with an aliphatic radical having from about 8 to about 20 carbon atoms. Further, we have found thateifective promoters are also obtained wherein both hydrogens on an amino group are replaced by alkyl radicals having from about8 to 20 carbon atoms to give the higher di-alkyl derivatives.

The compounds which we use in carrying out the process of th present invention maybe prepared by any satisfactory method and the invention is not particularly concerned with their method of preparation. These compounds may be conveniently prepared by reaction of a higher alkyl primary or secondary amine with the hydrohalide salt of lower S-alkyl pseudo-thiourea, pseudo-guanylthiourea, pseudo-monothiobiuret, dr pseudo-dithiobiuret to yield respectively the in which R is an alkylradical containing from 8 to 20 carbon atoms, R is hydrogen or an alkyl radical containing from 8 to 20 carbon atoms, R is an alkyl radical containing from 1 to 3 carbon atoms, and X is a halogen radical.

The hydrohalides of the lower alkyl pseudo compounds used in the above reactions may be conveniently-prepared by the action of a lower alkyl halide, such as ethyl iodide, on thiourea, guanylthiourea, monothiobiuret or dithiobiuret,

respectively.

The higher alkyl guanidines may also be prepared by the reaction of cyanamide with the hydrochlorides of higher monoor di-alkyi amines.

The higher alkyl biguanides may also be prepared by the. reaction of dicyandiamide with the hydrochlorides of higher monoor di-alkyl amines.

We do not limit ourselves to the use of these compounds prepared by any particular method, nor to the use of the hydrohalide salts of such compounds. The free'base may be used, and we also include the use of other salts (such as acetate) produced from the free base.

Examples of representative compounds falling within the scope of our invention include the following: unsymmetrical di-octyl guanidine hydrob'romide, cetyl guanidine hydroiodide, lauryl 23.2 grams of s=my1 pseudo-thiourea hydroiodide and 20 grams of "Lorol amine (technical mixture Cs-Cm primary aliphatic amines, averaging about C13) in 50 cc. of anhydrous ethanol was heated under reflux on a steam bath for 8 hours with evolution of ethyl mercaptan. The alcohol was then completely removed'by distillation under reduced pressure. The product was a light-brown crystalline paste, soluble in water to give a soapy" solution.

2. "Lorol biguam'de hydroiodide Same procedure as 1 using 18.5 grams of S-ethyl pseudo-guanyl-thiourea. hydroiodide and 13.5 grams of. Lorol amine in cc. of anhydrous ethanol. The product was similar to that obtained in l.

3. Lorol guanylthiourea hydroiodide Same procedure as 1 using 29.1 grams of S-ethyl pseudo-dithiobiuret hydroiodide and 20 grams of Lorol amine in 100 cc., of anhydrous ethanol. The product was a yellow paste, soluble in water to give a "soapy solution.

The compounds mentioned heretofore and which are useful in 'carrying out our invention are usually homogeneous, viscous pastes which will combine with acids, such as formic, acetic, hydrochloric, hydrobromic, and the like, to yield salts which are soluble in water. They may be used in flotation processes in the form of these water soluble salts or the free base may be used provided satisfactory dispersion is obtained.

While, as stated heretofore, the present invention is not limited to the treatment of any particular ore material, it has been found to be well suited for froth flotation of silica from phosphate rock and is the preferred embodiment of the invention. In the processes of removing silica from phosphate rock, the conditions are such that practically complete removal of the silica must be accomplished in order to produce a salable phosphate material. It is therefore an advantage of this invention that our reagents'not only effect satisfactory removal of the silica but are also economical in amounts used. The quantities required range from 0.2 pound per ton of ore depending upon the particular ore and the particular reagent. The invention is not, however, limited to such quantities.

The reagents of the present invention may be used alone or in mixtures with other promoters. They may likewise be used in conjunction with other cooperating materials such as conditioning reagents, oily or fat materials such as hydrocarbon oils, fatty acids, or fatty acid esters.

These new reagents are also adaptable for use in any of the ordinary concentrating processes such as film flotation, tabling, and particularly in froth flotation operations. The ore concentrating processes employed will depend upon the particular type or kind of ore which is being processed. For example, in connection with phosphate rock, relatively coarse phosphate bearing material, for example 28 mesh and larger, can be very economically concentrated by using these reagents in conjunction with a material such as fuel oil or pine oil and subjecting to concentration by the use of tables or by film flotation. The -28 phosphate rock material is best concentrated by means of froth flotation employing these improved silica promoters.

When the reagents of the present invention are employed as promoters in the froth flotation of silica from phosphate rock, which is the pre-' ferred embodiment thereof, the condition may be cordance with this invention.

stage fed into the flotation circuit.

In its most important aspect the present invention is utilized for the treatment of non-me- .tallic ore materials but it-is to be understood that our reagents under proper conditions may be used advantageously for the treatment of metallic ore materials.

Other improved phosphate flotation features which are known may be utilized in connection with the present invention such as splitting the phosphate flotation feed into a plurality of size ranges and floating each size separately as described in the U. S. Patent No. 2,156,245, the very complete removal of the slime prior to flotation which is also an aid to better results as pointed out in the Erickson application, Serial No. 325,'- 011 filed March 20, 1941, and the Mead and lvlaust' application Serial No. 320,121 flied February 21, 1940, which describes a process for classiiying and desliming phosphate flotation feed by means of a hindered settling classifier and which deslimed feed is well suited for treatment in ac- This'invention will be further illustrated by the following specific tests which are illustrations of the preferred embodiments thereof, but is not to be strictly limited thereby.

Flotation tests as follows were made on a sample of Florida. phosphate rock irom the Old Colony Mine near Brewster. A fine flotationfeed (-35 +200 mesh) was produced by scrubhing, polishing, and desliming until the ore ma-' ditioned with the pulp" for three seconds. Air was then admitted to the machine'an'd the resulting concentrate froth was collected .until the froth became barren. The flotation test products were-then filtered, dried, weighed, and assayed.

. The metallurgical data obtained in these tests are presented in Table I.

. 3 In the treatment of iron ores we have found that our reagent may be employed in flotation processes for removing the silica therefrom and the tailings' resulting from such processes are- R LITE N('J-NH-Y R! in which R is an alkyl radical containing from 8 to 20 carbon atoms, R is a member of the group consisting of hydrogen and an alkyl radical containing from 8 to 20 carbon atoms and Y is a member of the group consisting of hydrogen and is 1 l I H o radicals, and salts of such compounds to effect a substantially complete separation of the ore values from the acidic silicious'gangue thereby 3o producing a tailing high in phosphate and relatively low in gangue.

2. In the froth flotation process of separating acidic silicious-gangue from phosphate ore values, the step which comprises subjecting the ore to froth flotation in the presence of an effective amount of a product of the group consisting ofthose represented by the following formula:

in which R is an alkylradical containing from 8 to 20 carbon atoms, R is a member. of the group consisting of hydrogen and an alkyl radical containing from 8 to 20 carbon atoms, and Y is a. member of the group consisting of hydrogen and I radicals, and salts of such compounds to effect a substantially complete separation of the ore Table I Concentrate Tailing I Feed Test N0. perce'n Dist Dist Reagents ag gg insol. Percent Percent permit Percent Percent permit wt.. insol. insol wt. insol.

1 54.54 on 87.59 98.00 38.98 2.79 gi t; 2 54.54 58.34 88.14 o4.2e' 41.66 7.50 o 3% Pineoil .i 0.12

a Lauryl guanidine hydroiodide. b Lauryl blguanide hydroiodide.

- c Lauryl gusnylthiourea hydroiodide.

. terial and a cement product is produced which hasgreatly improved properties.

' valuesfrom the acidic silicious gangue thereby producing a tailing high in phosphate and rela-g tivelylow in gangue. 7 a

3. In the froth flotation process of separating acidic silicious gangue from phosphate ore "values, the step which comprises subjecting the ore to froth flotation in the presence of an eflective amount of a product of the group consisting of those represented by the following formula:

the step which comprises subjecting the ore to froth flotation in the presence of an effective amount of a product of the group consisting of those represented by the following formula:

, R 1 :11 in which R is an alkyl radical containing from 8 to 20 carbon atoms, R is a member of the group consisting of hydrogen and an alkyl radical containing from 8 to 20 carbon atoms; and X is a halogen radical, and salts of such compounds to effect a substantially complete separation of the ore values from the acidic silicious gangue thereby producing a tailing high in phosphate and relatively low in gangue.

5. In thefroth flotation process of separating acidic silicious gangue from phosphate ore values, the step which comprises subjecting the ore to froth flotation in the presence of an effective amount of a product of the group consisting of those represented by the following formula:

R NH'HX -NHCNH:

in which R is a member of the groupconsisting of hydrogen and an alkyl radical containing from 8 to 20 carbon atoms, and X is a halogen radical, and salts of such compounds to effect a substantially complete separation of the ore values from the acidic silicious gangue thereby producing a tailing high in phosphate and relatively low in gangue. I

6. In the flotation process of separating acidic silicious gangue from phosphate ore values, the step which comprises subjecting the ore to froth flotation in the presence of an effective amount of unsymmetrical di-octyl guanidine hydrobromide to effect a substantially complete separation of the ore values from the acidic silicious gangue thereby producing a tailing high in phosphate and relatively low in gangue.

7. In the flotation process of separating acidic silicious gangue from phosphate ore values, the.

step which comprises subjecting theme to froth flotation in the presence of an efiective amount of lauryl blguanidc hydrochloride to efiect a sub- 7 stantially complete separation of the ore values from the acidic silicious gangue thereby producing a tailing high in phosphate and relatively low in gangue.

HAROLD M. DAY. ELMER W. GIESEKE. 

